259 SECTION 502 APPROACH SLABS
502.1 -DESCRIPTION : This work shall consist of reinforced Portland cement concrete approach slabs for bridges, constructed on the completed and accepted subgrade, subbase or other base course, in accordance with these Specifications and in reasonably close conformity with the lines, grades and dimensions specified on the Plans or established by the Engineer.
502.2 -MATERIALS : Materials for this wor k shall conform to the requirements for materials in Section 501 except as modified. Class B concrete, under the provisions of Section 601, may be used in lieu of the concrete in 501, in which case materials and batching requirements for this work shall c onform to the requirements for 601. Compressive strength tests for acceptance of concrete shall be conducted in accordance with 601.4.4. Reinforcing steel shall conform to the requirements prescribed in Section 602.
CONSTRUCTION METHODS
Construction methods and equipment used for this work shall conform to the requirements prescribed for construction methods and equipment in Section 501, except as modified.
502.3 -FORMS : Side forms may be of steel or wo od. Forms shall not be removed for at least 24 hours after the concrete is placed.
502.4 -PLACING : The subgrade or base shall be thoroughly moistened immediately prior to placing the concrete. The concrete shall not be placed until the forms and reinforcing steel have been checked. The method and sequence of placing concrete shall be approved by the Engineer. Vibrators shall be so manipulated as to work the concrete thoroughly around the reinforcement and imbedded f ixtures and into corners and angles of the forms.
502.5 -JOINTS : Approach slabs shall have longitudinal joints in line with the longitudinal joints of the adjacent pavement. Longitudinal joints shall be sawed to a minimum depth of one -fourth of the plan depth of the slab plus ¼ in ch; the width shall be ¼ in ch, with a tolerance of plus or minus 1/16 in ches. Sawing shall be performed within five days after the slab is placed and prior to opening to construction traff ic. Joints shall be sealed in accordance with the requirements of Sections 501.17 and 503.
502.6 -CURBS : The safety curbs shall be constructed using the same type of concrete as for the approach slab and shall be in acc ordance with the Plans. The finish of the curb shall be in accordance with
260 502.7 -METHOD OF MEASUREMENT : The quantity of work done will be measured in square yards of "Portland Cement Concrete Approach Slab" complete in place and accepted; the area will be measured to the extremity of the concrete.
502.8 -BASIS OF PAYMENT : The quantity, determined as provided above, will be paid for at the contract unit price bid for the item below, which price and payment shall be full compensation for furnishing all materials including reinforcing steel, such transverse and longitudinal joints, joint filler, dowels and curbs, and all labor equipment, tools and incidentals necessary to complete the work.
502.9 -PAY ITEM : ITEM DESCRIPTION UNIT 502001 -* "thickness" Portland Cement Concrete Approach Slab Square Yard
* Sequence number “thickness” in inches
261 SECTION 503 SEALING CRACKS IN CONCRETE PAVEMENT
503.1 -DESCRIPTION : This work shall consist of the cleaning and sealing of cracks in concrete pavemen t in the manner and subject to the conditions and regulation prescribed. The location of the cracks to be sealed shall be shown on the plans or as directed by the Engineer.
503.2 -MATERIALS : The crack sealant material shall be in accordance with Section 708.3. The filler or back -up material shall be in accordance with Section 708.4.2, shall meet the requirements of the Sealant Manufact urer, and shall be appropriate for outdoor applications.
CONSTRUCTION METHODS
Old filler and foreign material in the cracks shall be removed. The cracks shall then be sealed as prescribed. Other means and/or methods recommended by the Sealant Manufacturer and approved by the Engineer may be used.
503.3: Blank
503.4 -PREPARATION OF MATERIAL BEFORE USE : Before charging the compound into the melting unit, the unit shall be free from all foreign material. If the type of heater to be used requires that the sealing material as shipped, be cut into smaller pieces before melting, the method used is subject t o approval by the Engineer. The heating kettle used for melting sealing materials shall be of the indirect heating or double boiler type, using oil as the heat transfer medium. It shall have a thermostatically controlled heat source, a built -in automatic agitator, and thermometers installed to indicate both the temperature of the melted sealing material and that of the oil bath. Other methods of indirect heating approved by the Engineer may be used. A positive means of controlling the temperature of the heat transfer medium at all points in the system shall be incorporated in the heater. Sealing material shall be uniformly heated until the pouring temperature recommended by the Sealant Manufacturer is reached. Should the maximum recommended pouring tem perature be exceeded, the material will be rejected. The material shall be poured as soon as possible after the pouring temperature is reached. Only sufficient material for the day’s operation shall be heated each day. Other means and/or methods recomme nded by the Sealant Manufacturer and approved by the Engineer may be used.
503.5 -PREPARATION OF CRACKS FOR SEALING : Cracks should be widened with a saw to a minimum width of ½ inch and to a depth necessary to provide a 1:1 width to depth ratio including room for the backing material, if necessary. Cracks greater than ½ inch width, do not require saw cutting. Unless otherwise noted, sealing concrete pavement joints shall be applied as outlined in Section 510 and cracks greater than one ( 1) inch width shall be repaired as outlined in Section 507. The cracks shall be thoroughly cleaned of all loose scale, dirt, dust, other foreign matter, old sealant and loosely stuck par ticles of mortar and aggregate, so that dry, sound, and clean surfaces result. The use of any tool which results in damage to the pavement is prohibited. Just